This invention relates to a shaker of the type having a shake table and a plurality of support legs which are eccentrically driven with respect to their shafts respectively.
Conventional shakers used in shake culture and the like include those shown in FIGS. 6-8, each of support legs A has threaded lower end which is screwed in one of tapped holes B eccentrically arranged on or through a central support disc D. The central support disc D secured to a central shaft C is rotated by a motor 3, while the peripheral support discs D' such as those disposed on four corner portions of a fitting plate 2 shown in FIG. 7 are rotated by the support legs A' which are per se eccentrically driven around the shafts C' respectively, since the peripheral support legs A' are secured to a back plate 7a of a shake table 7 which is driven through the central support leg A and the central disc D by the motor 3. With this arrangement, the locations or distances of the peripheral support legs A' relative to or from the tapped holes B' of the support discs D' must be exactly identical with each other, and if there exist any discrepancies between them, for example as shown in FIG. 7, it is either difficult or impossible to mount the shake table 7 on the discs D, D' with the threaded end portions fully screwed in the tapped holes B, B'. Further, with this arrangement, it is difficult or impossible to adjust or change the eccentricity of the support legs A, A' from the shafts C, C', and if required to doso, the formers A, A' themselves must be substituted with appropriate ones which have such desired eccentricity.
While, another prior art shaker of FIG. 8, viz., in Japanese Patent Publication No. 36-6950 can be advantageously adjusted or changed with respect to the eccentricity of the support legs A, A' from the shafts C, C' with employment of such construction that contains an adjust screw E which laterally moves the shaft A and a plurality of perpheral adjust sleeves F which can be moved on support rods H and fastened by screws G; in FIG. 8, a transmission belt from the motor 3 is not illustrated. However, this arrangement is very complicated in construction and further such adjustment must be effected each time with respect to every peripheral support legs A'.